Gallocyanin dye.



UNITED STATES PATENT OFFICE.

WILHELM LOMMEL, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY, A CORPORATION OF' GERMANY.

GALLOCYANIN DYE.

No Drawing.

To all whom 'it may concern:

Be it known that I, WILHELM LOMMEL, doctor of philosophy, chemist, citizen of the German Empire, residing at Elberfeld, Germany, have invented new and useful Improvements in Gallocyanin Dyes, of which the following is a specification.

In United States Letters Patent 856537 a dyestuif of the oxazin series is described which is chemically decarboxylated gallocyanin derived from nitrosodimethylanilin and gallic acid. The gallocyanin derived from nitrosodiethylanilin and gallic acid is not particularly described and my experience is that by the process hitherto known for the production of these compounds it cannot be obtained in technical yields. I have found a process for its production which consists in using for the condensation salts of the itroso compound of diethylanilin with such acids as form with the nitroso compound diflicultly soluble salts.

I have now found that a new coloring mat ter of the oxazinseries is produced from gallocyanin (obtained by the action of nitrosodiethylanilin on gallic acid) by splitting oil from diethylgallocyanin the carboxylic group 6. g. by heating the base until a test portion is soluble in hydrochloric acid of 20 B. with a pure blue color and is insolu-: ble in sodium carbonate solution. These tests readily distinguish the new dye from diethylgallocyanin which is soluble in sodium carbonate solution and dissolves in hydrochloric acid of 20 B. with a red color.

The following example will further lllustrate my invention, the parts belng by Application filed February 19, 1910. Serial No. 544,870.

weight:l00 parts of gallocyanin (obtained from nitrosodiethylanilin and gallic acid) in the shape of its salt. with hydrochloric acid are heated for several hours with an aqueous solution of 20 parts of NaOH. The reaction is complete when a test portion is insoluble in a sodium-carbonate solution I and dissolves in hydrochloric acid of 20.

B. with a blue color. The base is filtered oil and converted into its hydrochlorid.

The hydrochlorid of the new dyestufi is after drying, a' dark green powder soluble in water with a violet color. The new dye is distinguished from diethylgallocyanin from which it is produced, by giving 1n printing purer shades. It yields upon reduction the leuco compound described in my other ap plication for Letters Patent of same date from which it can be produced by oxidation.

I claim The herein-described new dyestufi obtainable from diethylgallocyanin, which dyestuff in the shape of its hydrochlorid after drying a dark green powder soluble in water' with a violet color, being distinguished from diethylgallocyanin by giving in printing purer shades; being soluble in hydrochloric acid of 20 B. with a pure blue color, and being insoluble in sodium carbonate solution, substantially as described.

In testimony whereofl have hereunto set my hand in the. presence of two subscribing witnesses.

WILHELM LOMMEL. [L. s.] Witnesses:

O'r'ro KoNIG, WILLY KLEIN. 

